1. Field of the Invention
This invention relates to new peptides useful as a medicine. This invention also relates to processes for preparing new peptides.
2. Description of the Prior Art
An active peptide, Pro-Hyp-Gly-Ala-Gly, (hereinafter referred to as compound P), is known from Japanese Patent Application (OPI) No. 165356/82 (the term "OPI" as used herein means an "unexamined published application"). This compound has potent anti-arrhythmic and platelet-agglutination preventing activity.
Compound P showed low toxicity and was expected as a remedy against ischemic cardiac insufficiencies. However, its effective dose for oral administration is rather large compared with conventional drugs, and its action does not last long as is apparent from its half-life in the blood as short as about ten minutes. Therefore, improvement has been desired.